1. Field of the Invention
This invention is related to a therapeutic composition. More specifically, this invention provides for a therapeutic drug with an enteric coating and a method for protecting the therapeutic drug.
2. Description of Prior Art
Many pharmaceutical preparations that are administered orally pass through various gastrointestinal environments before reaching the area where their effectiveness is desired. In route to this effective location the preparation may be inactivated by salivary juices and/or the acid environment of the gastric lumen. The preparation may be irritating to the mucosal tissue along the way or it may be absorbed with undesired systemic effects.
These effects on the preparations have led me to posit that it would be most advantageous if some sort of coating of therapeutic materials could be selectively "triggered" at the desired action site in the gastrointestinal (GI) tract. Ideally, the material would be inactive in the GI tract before this site was reached and would be, in some fashion, inactivated from undesired action after the desired site was visited or the action accomplished.
In the past, the use of such things as polysaccharides or cellulose coatings have attempted to speak to this need. These coatings are, however, "activated" by their hydrophillic activity and the coating dissolves as a function of time and exposure to an H.sub.2 O environment; that is, it is a non-specific response. In this age of increasingly potent (and at times toxic) materials, which are used for such things are chemotherapy, this non-specificity is a liability.
U.S. Pat. No. 874,310 discloses a pharmaceutical coating of maizin, a proteid, around a capsule. U.S. Pat. No. 3,004,893 teaches trypsin coated pills. The combination of trypsin and polyamino acid polymer coatings is disclosed in U.S. Pat. Nos. 3,167,485 and 3,331,814 for biodegradable sutures. These patents, nor any other prior art, teach my improved method and composition of this invention.